Medtronic Inc. is backing findings of a study that raised serious safety concerns about Riata and Riata ST defibrillator leads made by rival, St. Jude Medical Inc. The study, conducted by Dr. Robert Hauser and published in the journal Heart Rhythm, found that the Riata leads were associated with higher death and failure rates than Medtronic’s Quattro defibrillator leads.

A defibrillator lead is a thin wire attached to the heart wall that delivers an electrical impulse via an implantable defibrillator. Hauser’s Riata study, published late last month, was based on a search of the U.S. Food and Drug Administration (FDA) Manufacturers and User Facility Device Experience (MAUDE) database. The study found that “high-voltage failures” of the Riata and Riata ST leads had caused 22 deaths, more than were associated with Medtronic’s Quattro wires. According to a Reuters report, Hauser said the Riata lead failures appeared to be caused by insulation defects that resulted in short-circuiting between high-voltage components.

Last Friday, St. Jude demanded that Heart Rhythm retract Dr. Hauser’s study, and said its analysis of the FDA database had produced different findings. Specifically, the company said found 377 reports of deaths involving Quattro Secure wires, while Hauser reported 62. The company’s analysis of Riata lead events in the database found 74 deaths, while Hauser reported 71. St. Jude said it used the same criteria as Hauser had in performing its analysis.

St. Jude also criticized Hauser’s used of the MAUDE database for his study, asserting that doing so caused his findings to be biased “against manufacturers that more transparently report on device malfunctions” The company claimed that Medtronic reports the least amount of detail regarding adverse events compared with other companies in the industry.

Now Medtronic has reported that its analysis of the FDA database yielded results that mirrored Dr. Hauser’s.

“The conclusions we have reached about Sprint Quattro are consistent with what Dr. Hauser found, and we confirm his results related to Sprint Quattro,” Medtronic said in a statement emailed to Reuters.

According to a report from MassDevice.com, St. Jude over the weekend accused its rivals of using the Riata issue to smear its name in order to gain an edge in the slumping cardiac rhythm management arena.

“This has become a topic of competitive marketing,” St. Jude CEO Daniel Starks told the New York Times, according to MassDevice.com. “We have competitors going to physicians and informing them, either incompletely or mistakenly, of a competitively hostile view of the facts.”

But officials at Medtronic scoffed at Stark’s assertion.

“Numerous other institutions have issued case studies and manuscripts on this issue,” a Medtronic spokesperson told MassDevice.com. “This is very clearly not a marketing campaign; this is a serious issue with a device in the marketplace.”

This is not the first time the Riata defibrillator leads have raised serious safety concerns. In December 2010, St. Jude stopped selling the Riata and Riata ST wires and warned doctors to stop using them. At the time, the company reported to doctors that the wires had a 0.47% rate of “insulation abrasion,” which occurs when the wires poke through their insulation, after 9 years of use. As we reported previously, St. Jude launched an official recall of the Riata wires in December 2011, and revealed that two patients had died during procedures to remove the leads.

Last week, St. Jude announced it would stop selling its QuickSite and QuickFlex leads because of the same issue that caused the Riata recall. As we reported, the company said the conductive ends of the wires break through the silicone insulation in about 3 to 4 percent of the patients who’ve had them implanted. St Jude acknowledged receiving 39 reports of the occurrence, but said it has not caused any injuries or device malfunction.

St. Jude’s announcement applied only to QuickSite and QuickFlex leads sold before 2008. After that date, the leads were covered in a “hybrid” insulation that’s purportedly not prone to the same errors, the company said.